Obviously Sinister Serpent was the king, back in its day. I thoroughly loved it and a pair of Night Assailants, but of course, those days are over for good.
If you don't mind going for themes, there's some tricks:
Elemental Heroes can use Ocean on the field to bring a hero back from the graveyard or field to the hand every turn you can just chuck right back to the graveyard for another discard cost.
Volcanics can have a nice little discard/draw engine if you don't mind paying 500 life points each turn, and you have Card Trader out on the field, use Volcanic Shell, when one's in the graveyard, and keep pulling one to your hand, then using Card Trader to shuffle it back into the deck to draw another card you can use or discard. A little costly, but effective.
Or, if you /really/ want to get wacky, run a deck with lots of discards, two Ojamagics, and three of each Ojama, then Heart of the Underdog, and other Noral monsters. It's not exactly effective to win with, but it gives you plenty of discard fodder!